1. Field of the Invention
This invention relates to the art of manufacturing or processing of continuous webs, such as conventional polymer films, continuously moving at typical elevated speeds of between 10 and 200 meters per minute and which are to be wound onto a sequence of cores normally supplied from an automated core delivery means or magazine and without stopping movement of the web.
2. Description of the Prior Art
Winding machines for continuous operation with flexible webs are well known in the art, cf. U.S. Pat. Nos. 1,687,928; 2,915,255; 3,494,566 and 4,191,341.
A common feature of many prior art winders is a device for receiving and cutting a substantially endless web into portions of predetermined length and for winding each portion onto an empty winding mandrel or core, e.g. rods or tubes made of cardboard, plastic or the like materials.
Generally, cutting means or knives are used to separate a preceding length of the web from a subsequent portion. The leading edge of each web portion is brought into contact with a fresh core, or vice-versa, and a sticky substance or material, typically a double-sided adhesive tape, provided at the core surface is used to fix and hold the leading edge of the web on the core while the latter is rotated to start and continue winding.
A first disadvantage of this conventional approach is that a separate step is needed for applying the adhesive tape or the like sticky substance to the core; another disadvantage is that sticky materials tend to lose or change their adhesive properties, e.g. because of deposition of dust or an unintentional contact upon handling, or due to detrimental effects caused by prolonged storage, temperature impact, and the like condition.
Another essential and functional disadvantage of using conventional sticky materials for adhesion of the leading edges on the cores is that a crepe-like wrinkling effect or a shock-like tensioning of the web may occur due to the instantaneous impact of such adhesion when the core rotates at a peripheral speed that is not exactly the same as the linear speed of the moving web.